Field of the Invention
The present invention relates to a liquid ejection head used in a liquid ejection apparatus, and the liquid ejection apparatus.
Description of the Related Art
In the liquid ejection head, there are cases where ejected bubbles are generated from the vicinity of an ejection port along with ejection. The ejected bubbles generated along with ejection float in a flow passage with the aid of their own buoyancy and remain above the flow passage. In the case where the flow rate of liquid in the flow passage is increased by an ejecting operation, the velocity of the liquid in the flow passage is increased, and small bubbles derived from the ejected bubbles which remain above the flow passage are carried away by the flow and fall downward toward an ejection element substrate. In the case where the small bubbles which have fallen downward in this way reach an ejection port, the small bubbles sometimes generate nonejection of not ejecting the liquid. In a case where generation places and generation timing of nonejection are randomly distributed, it is difficult to visually confirm such nonejection, and thus nonejection may rarely deteriorate sensory image quality.
In liquid ejection heads that supply the liquid to the ejection element substrate provided with a comparatively long ejection port array, there is a liquid ejection head having a long-hole flow passage which guides the liquid to a long hole-like liquid supply port of the ejection element substrate and which is widely opened in a long-hole shape. Such a structure makes it possible to supply a large amount of liquid simultaneously and uniformly to the entire ejection element substrate in comparison with a structure of a flow passage accompanied with a steep throttle directly upstream of the ejection element substrate.
In Japanese Patent Laid-Open No. 2011-079246, there is disclosed a liquid ejection head in which a beam-shaped member is provided in the flow passage for reinforcement and the like in order to prevent deformation in the process of manufacturing the long-hole flow passage.
There are cases where flow velocities are different from each other between one side and the other side of the long-hole flow passage in a longitudinal direction depending on the structure of the liquid ejection head. In a case where the beam-shaped member is provided in the flow passage and a difference in flow velocities between the flow passages on the both sides of the beam-shaped member is large as that in Japanese Patent Laid-Open No. 2011-079246, a flow directed from a high-velocity flow passage toward a low-velocity flow passage is generated at a downstream-side terminal of the beam-shaped member.
At this time, also the small bubbles having fallen downward together with the flow of the liquid are carried away toward the low-velocity flow passage side. However, in many cases, the small bubbles are sucked into a flow directed toward the ejection port of the ejection element substrate in the case of passing through the downstream-side terminal of the beam-shaped member. Therefore, there are cases where nonejection frequently occurs in the ejection port located directly under the beam-shaped member and causes deterioration of the image quality.